As far as I know, it isn’t a common experience for someone to feel hunger pangs after looking at, say, a living cow or pig. Instead, we feel hungry when we look at food that has been prepared for consumption (such as a steak or bacon). Even uncooked meat probably doesn’t elicit that reaction in many of us, nor would a field of corn (versus buttered corn on the cobb).
In comparison, I imagine that for other carnivorous animals, the sight of a living prey species would actually activate the “yummy food” areas of their brain and make them want to eat. I imagine that an owl, for instance, would see a mouse running across a field and feel an urge to put it in its mouth.
My question: how far back would we have to go to find that most humans would look at a wildebeest or bird and feel hunger pangs?